Anti-pendulation rigging for cranes



July 2, 1963 v. c. FARRELL ANTI-PENDULATION RIGGING FOR CRANES Filed June 22, 1961 N Yr INVENTOR Maw? 9 ATTORNEYS United States Patent 3,095,977 ANTI-PENDULATION RIGGING FOR CRANES Valdemar C. Farrell, Rte. 1, Box 172, Harwood, Md.

Filed June 22, 1961, Ser. No. 118,829 4 Claims. (Cl. 21258) This invention pertains to swinging boom cranes, and particularly to the rigging of gear of such cranes to prevent undesirable pendulation or swinging of the load when the boom is rapidly slewed and/or topped.

The most common form for rigging of the load fall of a crane is to simply take it over a roller or pulley mounted at the head of the boom wherefrom it extends downwardly to the load. However, rapid slewing of the boom, and/ or topping thereof results in pendulation or swinging of the load in any direction. This means that these movements of the boom head cannot be rapidly changed in speed and even the most skillful operator has difliculty in handling a crane under these circumstances and still be efiicient in use and time. One prior arrangement for meeting the situation has been to pro vide a cross member at the head of the boom with a roller or pulley mounted on both ends thereof, equally spaced laterally from the boom head, with two load falls running over these pulleys and downwardly to the load whereat both falls are fixed. This has permitted control over the pendulation of the load when the boom is slewed, due to the fact that in effect a triangle is formed with a base being the length of the spacing member across the boom head, and the sides being the two load falls which meet at the load. The just described rigging however, does not prevent pendulation or a swinging of the load in a plane which includes the axis of the boom and the load, when the boom is rapidly topped. It has been proposed that a third load fall be run from a point intermediate the head and heel of the boom to the load, for acting jointly with two spaced apart load falls as described hereinabove, for arresting also the swinging of the boom head when the topping is altered. However, due to the upward inclination of the boom, this means that the fall from the load to the point on the boom which is down from the head, is shorter than the fall or falls to the boom head. Wherefore, three lines being involved, very special Winching of the third fall is necessary, with a difierential in speed with respect to the other falls so as to properly distribute the weight of the load among the falls.

In accordance with the present invention pendulation or swinging of the load due to slewing on the one hand and due to topping on the other hand, or both, is prevented, and this is done with the use of but two falls. The manner in which this is accomplished can be best understood by reference to the illustrative embodiment which will now be fully described.

From the foregoing, it is apparent that the principal Object of the present invention is to provide a novel rigging for a crane boom, that will prevent undesired swing ing of the load as a consequence of both slewing and topping operations. Further objects and the entire scope of the invention will become apparent from the following explanation of an illustrative embodiment and from V Patented July 2, 1963 "ice A boom 10 is shown mounted in a ball joint 12 at its heel for a universal movement. The boom itself is characterized by two side members 1011 and 1% which extend in a diverging manner to a main across member at the head of the boom. Toward the heel of the boom is a further cross member 10d at the ends of which the members 10a and 10b make an angle toward the boom heel 12. Other cross members such as 10c together with triangulation members such as 10; may be employed to provide suitably rigidity to the boom as desired.

At one end of the cross member 10c there is rigged a pulley 14 over which a first fall line 16 runs. Line -16 in one direction runs to point 18 whereat it is fixed to the load 20. In the other direction from pulley 14- the fall line 16 runs over a pulley 22 near the heel of the boom, to the fall winch (not shown). At one end of the cross member 10d is a pulley or roller 24 over which a second fall line 26 runs. The pulley 24 is on the end of member 10d which is on the opposite side of the center line of the boom from the pulley 14. It will also be observed that the cross member 1041 and the pulley member 24 are mounted an appreciable distance down the boom, in the direction of the boom heel 12. Preferably, the distance down the boom by the cross members 100 and 10d should be such, in relation to the length of these members, that in a plan view of the boom a line drawn between pulleys 14 and 24 will be at 45 to the center line of the boom structure.

The second load fall 26 in one direction runs to the point 18 whereat it is fixed to the load 20 and in the other direction from pulley 24 the fall 26 runs over the pulley 22 and joins with the fall 16 to the fall winch.

Any manner of slewing and/or topping of the bottom may be employed. So as to show an illustrative embodiment of such gear, the boom and rigging as thus far described, are shown mounted in conjunction with two upright posts 28 and 30, joined at the top by a cross member 32. This is the typical arrangement found aboard ship, where considerable use of cranes exist. Attached to the ends of cross member 10c of the boom are lines 34 and 36 which are joined together at a point 38 to which is secured a pulley 40 which runs in the bight of a topping line 42 which has anchor points on the cross member 32. One anchor point 44 is preferably at the center of member 32, While the other anchor point is preferably at the top of post 28, in this case the anchor point being in the form of a pulley 46 over which runs the topping line =42 which proceeds from the pulley 46 to a topping winch (not shown).

For further control of the boom, a vang line 48 runs from a point of attachment at or near the head of the boom, such as an attachment at point 50 on the end of cross member 10d down to and over a pllley 52 which is secured to the deck or other fixed structure preferably on a line which runs through the lower ends of the mast 28 and 30. From the pulley 52 the vang line 48 runs to a vang Winch (not shown). In operation, when the vang line 48 is payed out from the winch, so as to lengthen the distance between pulley 52 and the point 50 on the boom, the pulley 40 runs in the b ight of topping line 42 and the boom head gravitates downwardly and outwardly away from the mast 30 and pulley 52. Paying out the topping line 42 from its winch serves to lower the boom head, and the boom head is lifted or topped upwardly by reason of pulling in the total line between anchor point 40 and pulley 46. Taking in on the vang line 48 moves the boom to the side toward post 30. Preferably the heel 12 of the boom is located (as shown best in FIGS. 1 and 3) a short distance behind the plane of the posts 28 and 30. This prevents the boom tending to go over does not result in swinging of the load in a plane transverse to the center line of the boom because of the triangulation present as seen in FIGURE 2, transverse to the axis of the boom. Moreover, it will further be seen that with but the two falls 16 and 26, rapid topping of the boom still does not result in pendulation. This is due to the triangulation presented in the vertical plane which includes the center line of the boom, as best seen in FIG- URE 1. It thus becomes apparent that in accordance with the present invention, as distinct from the prior art, the undesirable pendulation or swinging of the boom in the slewing direction and in the topping direction have been eliminated, and this has been accomplished by the elimination of the third fall heretofore required for this purpose. In effect, the function of the third fall has been retained, but as a component of equipment it has been eliminated, which is a very considerable advantage.

The bridle consisting of parts 36 and 38 tends to prevent the boom from twisting about the axis thereof when the slewing velocity is changed. Any such twisting tendency may be further prevented by replacing the ball joint at heel 12 with a fitting (not shown) which has freedom to rotate only in the topping and slewing directions. It is to be understood that the foregoing illustrative embodiment of the invention has been described in detail only for the purpose of explanation and the true scope of the present invention is to be determined from the appended claims.

I claim:

1. In crane apparatus, a boom having a heel and a head, means for slewing said boom, means for topping said boom, means at a first point a given distance from the boom heel and a given distance to one side of the center line of the boom for guiding a first fall line thereover, and means at a second point closer to said boom heel than the first point and on the opposite side of the center line of the boom for guiding a second fall line thereover, a load hook means, the said first and second fall lines being fixed together at the load hook means as sole support therefor.

-2. Apparatus as in claim 1 wherein the respective fall guiding means are located so that a straight line joining same describes substantially a degree angle with the axis of the boom.

3. Apparatus as in claim 2 wherein the means for topping the boom comprises a bridle having parts extending from a central point to two points of attachment located to either side of the boom.

4. Apparatus as in claim 1 wherein the means for topping the boom comprises a bridle having parts extending from a central point to two points of attachment located to either side of the boom.

References Cited in the file of this patent UNITED STATES PATENTS 2,255,568 Page Sept. 9, 1941 2,529,454 Marcantonio Nov. 7, 1950 2,805,781 Senn Sept. 10, 1957 

1. IN CRANE APPARATUS, A BOOM HAVING A HEEL AND A HEAD, MEANS FOR SLEWING SAID BOOM, MEANS FOR TOPPING SAID BOOM, MEANS AT A FIRST POINT A GIVEN DISTANCE FROM THE BOOM HEEL AND GIVEN DISTANCE TO ONE SIDE OF THE CENTER LINE OF THE BOOM FOR GUIDING A FIRST FALL LINE THEREOVER, AND MEANS AT A SECOND POINT CLOSER TO SAID BOOM HEEL THAN THE FIRST POINT AND ON THE OPPOSITE SIDE OF THE CENTER LINE OF THE BOOM FOR GUIDING A SECOND FALL LINE THEREOVER, A LOAD HOOK MEANS, THE SAID FIRST AND SECOND FALL LINES BEING FIXED TOGETHER AT THE LOAD HOOK MEANS AS SOLE SUPPORT THEREFOR. 